Note 9 - Pension Plans - Net Periodic Pension Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Service cost	$ 101	$ 104	$ 108
Interest cost	1,450	1,803	1,886
Expected return on plan assets	(1,721)	(1,910)	(1,685)
Recognized actuarial loss	438	179	236
Net periodic pension expense	$ 268	$ 176	$ 545